scholarly journals Decreased content of arachidonoyl species of phosphatidylinositol phosphates in pancreas of rats fed on an ethanol-containing diet

1992 ◽  
Vol 287 (3) ◽  
pp. 925-928 ◽  
Author(s):  
T Cronholm ◽  
M Viestam-Rains ◽  
J Sjövall
Keyword(s):  
Mass Spectrometry ◽  
Species Composition ◽  
Anion Exchanger ◽  
Fast Atom Bombardment ◽  
Liquid Diet ◽  
Lipophilic Anion ◽  
Phosphatidylinositol Phosphates ◽  
Phosphatidylinositol 4 ◽  
And Control

Phosphatidylinositol (PtdIns), phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol 4,5-diphosphate [PtdIns(4,5)P2] were isolated from the pancreas of rats fed an ethanol-containing liquid diet for 24 days and from the corresponding pair-fed controls. The isolation involved chromatography on a lipophilic anion exchanger in the phosphate form. The species composition was determined by fast-atom bombardment mass spectrometry. The compositions of PtdIns4P and PtdIns(4,5)P2 were similar to that of PtdIns, with the stearoyl/arachidonoyl species constituting about 32% of the total, compared with 38% in PtdIns. PtdIns(4,5)P2 contained a larger fraction of fully saturated species than PtdIns. The PtdIns species having an arachidonoyl group were about half as abundant in the ethanol-treated as in the control rats. The differences between ethanol-fed and control rats were qualitatively similar for PtdIns, PtdIns4P and PtdIns(4,5)P2, but were less marked for PtdIns4P and PtdIns(4,5)P2. The results indicate that the species compositions of PtdIns4P and PtdIns(4,5)P2 reflect that of PtdIns, and that the changes of PtdIns4P and PtdIns(4,5)P2 in ethanol-treated rats are secondary to changes in PtdIns.

Effects of Doping on the Electrochemical and Electrical Properties of Poly(2,5-di(2-thienyl)pyrrole)

1999 ◽  
Vol 64 (8) ◽  
pp. 1357-1368 ◽  
Author(s):  
Enric Brillas ◽  
José Carrasco ◽  
Ramon Oliver ◽  
Francesc Estrany ◽  
Víctor Ruiz
Keyword(s):  
Mass Spectrometry ◽  
Fast Atom Bombardment ◽  
Oxidation Potential ◽  
Ethanolic Solution ◽  
Pt Electrode ◽  
Reversible Process ◽  
Oxidation Potentials ◽  
Lower Productivity ◽  
Polymeric Chains ◽  
Linear Molecules

The electropolymerization of 2,5-di(2-(thienyl)pyrrole) (SNS) on a Pt electrode from ethanolic solution with LiClO4 or LiCl as electrolyte has been studied by cyclic voltammetry (CV) and chronoamperometry (CA). In both media, a quasi-reversible process has been indicated by CV, reversing the scan at low oxidation potentials. Under these conditions, reducible positive charges formed in both oxidized polymers are compensated by the entrance of anions from solution. Elemental analysis reveals that polymers generated at a low oxidation potential by CA contain a 21.03% (w/w) of ClO4- or a 9.56% (w/w) of Cl-. The poly(SNS) doped with Cl- presents higher proportion of reducible positive charges, higher polymerization charge and lower productivity. A much higher electrical conductivity, however, has been found for the poly(SNS) doped with ClO4-. Both polymers are soluble in DMSO, acetone and methanol. The dimer, trimer, tetramer and pentamer have been detected as soluble and neutral linear oligomers by mass spectrometry-fast atom bombardment. The analysis of polymers by infrared spectroscopy confirms the predominant formation of linear molecules with α-α linkages between monomeric units. A condensation mechanism involving one-electron oxidation of all electrogenerated linear and neutral polymeric chains is proposed to explain the SNS electropolymerization.

scholarly journals Hyperandrogenism by Liquid Chromatography Tandem Mass Spectrometry in PCOS: Focus on Testosterone and Androstenedione

2020 ◽  
Vol 10 (1) ◽  
pp. 119
Author(s):  
Giorgia Grassi ◽  
Elisa Polledri ◽  
Silvia Fustinoni ◽  
Iacopo Chiodini ◽  
Ferruccio Ceriotti ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Polycystic Ovary ◽  
Free Testosterone ◽  
Reference Intervals ◽  
Model Assessment ◽  
Homeostatic Model Assessment ◽  
Liquid Chromatography Tandem Mass ◽  
And Control ◽  
The Impact

The identification of hyperandrogenism in polycystic ovary syndrome (PCOS) is concerning because of the poor accuracy of the androgen immunoassays (IA) and controversies regarding which androgens should be measured. The aim of our study was to evaluate the impact of the assessment of testosterone (T) and androstenedione (A) by liquid chromatography in tandem with mass spectrometry (LC/MS-MS), in the diagnosis of PCOS. We evaluated 131 patients referred for suspected PCOS. Fourteen patients in total were excluded, some because of other diagnosis (n = 7) or incomplete diagnostic workup (n = 7). We measured T and A both by IA and LC-MS/MS in the 117 subjects included. We calculated free T (fT) by the Vermeulen formula and recorded clinical and metabolic data. 73 healthy females served as controls to derive immunoassays (IA) and LC-MS/MS reference intervals for T, fT and A. PCOS was confirmed in 90 subjects by IA and in 93 (+3.3%) by LC-MS/MS. The prevalence of biochemical hyperandrogenism in PCOS by LC-MS/MS increased from 81.7% to 89.2% if A was also considered. The most frequently elevated androgens were fT (73.1%) and A (64.5%) and they had similar levels of accuracy in differentiating PCOS and controls (0.34 ng/dL, Sn 91% Sp 89%; 1.16 ng/mL, Sn 91% Sp 88%, respectively). Free testosterone correlated with body mass index (BMI), homeostatic model assessment (HOMA)-index, glycated hemoglobin (HbA1c), and sex-binding globulin (SHBG). The results confirm that LC-MS/MS is slightly more sensitive than IA in the diagnosis of PCOS with LC-MS/MS detecting higher levels of fT and A. Moreover, assessment of fT and A by LC-MS/MS had a similar level of accuracy in discriminating between PCOs and control subjects. Lastly, fT by LC-MS/MS correlates with adverse metabolic parameters.

scholarly journals A revised primary structure for neocarzinostatin based on fast atom bombardment and gas chromatographic-mass spectrometry.

1984 ◽  
Vol 259 (17) ◽  
pp. 10801-10806
Author(s):  
B W Gibson ◽  
W C Herlihy ◽  
T S Samy ◽  
K S Hahm ◽  
H Maeda ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Primary Structure ◽  
Fast Atom Bombardment ◽  
Chromatographic Mass

scholarly journals Assignment of disulfide bonds in proteins by fast atom bombardment mass spectrometry.

1987 ◽  
Vol 262 (6) ◽  
pp. 2507-2513
Author(s):  
R. Yazdanparast ◽  
P.C. Andrews ◽  
D.L. Smith ◽  
J.E. Dixon
Keyword(s):  
Mass Spectrometry ◽  
Disulfide Bonds ◽  
Fast Atom Bombardment

scholarly journals Proton NMR and fast-atom bombardment mass spectrometry analysis of the melanoma-associated ganglioside 9-O-acetyl-GD3.

1985 ◽  
Vol 260 (27) ◽  
pp. 14556-14563 ◽  
Author(s):  
J Thurin ◽  
M Herlyn ◽  
O Hindsgaul ◽  
N Strömberg ◽  
K A Karlsson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fast Atom Bombardment ◽  
Proton Nmr ◽  
Mass Spectrometry Analysis ◽  
Spectrometry Analysis
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